Initial implementation of taglib MetadataExtractor

scanner/metadata/metadata.go

@@ -1,6 +1,25 @@
 package metadata
 
-import "time"
+import (
+	"fmt"
+	"os"
+	"path"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/deluan/navidrome/log"
+)
+
+type Extractor interface {
+	Extract(files ...string) (map[string]Metadata, error)
+}
+
+func Extract(files ...string) (map[string]Metadata, error) {
+	e := &taglibExtractor{}
+	return e.Extract(files...)
+}
 
 type Metadata interface {
 	Title() string
@@ -28,11 +47,122 @@ type Metadata interface {
 	Size() int64
 }
 
-type Extractor interface {
-	Extract(files ...string) (map[string]Metadata, error)
+type baseMetadata struct {
+	filePath string
+	fileInfo os.FileInfo
+	tags     map[string]string
 }
 
-func Extract(files ...string) (map[string]Metadata, error) {
-	e := &ffmpegMetadataExtractor{}
-	return e.Extract(files...)
+func (m *baseMetadata) Title() string       { return m.getTag("title", "sort_name") }
+func (m *baseMetadata) Album() string       { return m.getTag("album", "sort_album") }
+func (m *baseMetadata) Artist() string      { return m.getTag("artist", "sort_artist") }
+func (m *baseMetadata) AlbumArtist() string { return m.getTag("album_artist", "albumartist") }
+func (m *baseMetadata) SortTitle() string   { return m.getSortTag("", "title", "name") }
+func (m *baseMetadata) SortAlbum() string   { return m.getSortTag("", "album") }
+func (m *baseMetadata) SortArtist() string  { return m.getSortTag("", "artist") }
+func (m *baseMetadata) SortAlbumArtist() string {
+	return m.getSortTag("tso2", "albumartist", "album_artist")
+}
+func (m *baseMetadata) Composer() string        { return m.getTag("composer", "tcm", "sort_composer") }
+func (m *baseMetadata) Genre() string           { return m.getTag("genre") }
+func (m *baseMetadata) Year() int               { return m.parseYear("date") }
+func (m *baseMetadata) Comment() string         { return m.getTag("comment") }
+func (m *baseMetadata) Compilation() bool       { return m.parseBool("compilation") }
+func (m *baseMetadata) TrackNumber() (int, int) { return m.parseTuple("track", "tracknumber") }
+func (m *baseMetadata) DiscNumber() (int, int)  { return m.parseTuple("disc", "discnumber") }
+func (m *baseMetadata) DiscSubtitle() string {
+	return m.getTag("tsst", "discsubtitle", "setsubtitle")
+}
+
+func (m *baseMetadata) ModificationTime() time.Time { return m.fileInfo.ModTime() }
+func (m *baseMetadata) Size() int64                 { return m.fileInfo.Size() }
+func (m *baseMetadata) FilePath() string            { return m.filePath }
+func (m *baseMetadata) Suffix() string {
+	return strings.ToLower(strings.TrimPrefix(path.Ext(m.FilePath()), "."))
+}
+
+func (m *baseMetadata) Duration() float32 { panic("not implemented") }
+func (m *baseMetadata) BitRate() int      { panic("not implemented") }
+func (m *baseMetadata) HasPicture() bool  { panic("not implemented") }
+
+func (m *baseMetadata) parseInt(tagName string) int {
+	if v, ok := m.tags[tagName]; ok {
+		i, _ := strconv.Atoi(v)
+		return i
+	}
+	return 0
+}
+
+var dateRegex = regexp.MustCompile(`^([12]\d\d\d)`)
+
+func (m *baseMetadata) parseYear(tagName string) int {
+	if v, ok := m.tags[tagName]; ok {
+		match := dateRegex.FindStringSubmatch(v)
+		if len(match) == 0 {
+			log.Warn("Error parsing year from ffmpeg date field", "file", m.filePath, "date", v)
+			return 0
+		}
+		year, _ := strconv.Atoi(match[1])
+		return year
+	}
+	return 0
+}
+
+func (m *baseMetadata) getTag(tags ...string) string {
+	for _, t := range tags {
+		if v, ok := m.tags[t]; ok {
+			return v
+		}
+	}
+	return ""
+}
+
+func (m *baseMetadata) getSortTag(originalTag string, tags ...string) string {
+	formats := []string{"sort%s", "sort_%s", "sort-%s", "%ssort", "%s_sort", "%s-sort"}
+	all := []string{originalTag}
+	for _, tag := range tags {
+		for _, format := range formats {
+			name := fmt.Sprintf(format, tag)
+			all = append(all, name)
+		}
+	}
+	return m.getTag(all...)
+}
+
+func (m *baseMetadata) parseTuple(tags ...string) (int, int) {
+	for _, tagName := range tags {
+		if v, ok := m.tags[tagName]; ok {
+			tuple := strings.Split(v, "/")
+			t1, t2 := 0, 0
+			t1, _ = strconv.Atoi(tuple[0])
+			if len(tuple) > 1 {
+				t2, _ = strconv.Atoi(tuple[1])
+			} else {
+				t2, _ = strconv.Atoi(m.tags[tagName+"total"])
+			}
+			return t1, t2
+		}
+	}
+	return 0, 0
+}
+
+func (m *baseMetadata) parseBool(tagName string) bool {
+	if v, ok := m.tags[tagName]; ok {
+		i, _ := strconv.Atoi(strings.TrimSpace(v))
+		return i == 1
+	}
+	return false
+}
+
+var zeroTime = time.Date(0000, time.January, 1, 0, 0, 0, 0, time.UTC)
+
+func (m *baseMetadata) parseDuration(tagName string) float32 {
+	if v, ok := m.tags[tagName]; ok {
+		d, err := time.Parse("15:04:05", v)
+		if err != nil {
+			return 0
+		}
+		return float32(d.Sub(zeroTime).Seconds())
+	}
+	return 0
 }